xref: /aosp_15_r20/external/sg3_utils/inhex/nvme_write_ctl.hex (revision 44704f698541f6367e81f991ef8bb54ccbf3fc18)
1*44704f69SBart Van Assche# 64 byte NVMe, Write command (a NVM command) that is suitable for:
2*44704f69SBart Van Assche#       sg_raw --cmdfile=<this_file_name> --nvm --request=2048 <nvme_device>
3*44704f69SBart Van Assche#
4*44704f69SBart Van Assche# The address field (at byte offset 24, 8 bytes and little endian) gives
5*44704f69SBart Van Assche# special meaning to the highest address pointers:
6*44704f69SBart Van Assche#    ffffffff fffffffe         use address of data-in buffer
7*44704f69SBart Van Assche#    ffffffff fffffffd         use address of data-out buffer
8*44704f69SBart Van Assche#
9*44704f69SBart Van Assche# The data length field (at byte offset 36, 4 bytes and little endian)
10*44704f69SBart Van Assche# gives special meaning to the highest block counts:
11*44704f69SBart Van Assche#    fffffffe                  use byte length of data-in buffer
12*44704f69SBart Van Assche#    fffffffd                  use byte length of data-out buffer
13*44704f69SBart Van Assche#
14*44704f69SBart Van Assche# 512 byte logical block size is assumed. Write 4 blocks hence 2048 bytes.
15*44704f69SBart Van Assche# The first LBA written is 0x12345 and the namespace is 1. If successful the
16*44704f69SBart Van Assche# four blocks will be written out of the data-out buffer. Submission queue
17*44704f69SBart Van Assche# is used (the same queue that Admin commands use). The NVM opcode for the
18*44704f69SBart Van Assche# Write command is 0x1 and appears in the first command byte.
19*44704f69SBart Van Assche
20*44704f69SBart Van Assche01 00 00 00 01 00 00 00  00 00 00 00 00 00 00 00
21*44704f69SBart Van Assche00 00 00 00 00 00 00 00  fd ff ff ff ff ff ff ff
22*44704f69SBart Van Assche00 00 00 00 fd ff ff ff  45 23 01 00 00 00 00 00
23*44704f69SBart Van Assche03 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00
24*44704f69SBart Van Assche
25*44704f69SBart Van Assche# Notice NVMe uses its quirky "0's based" number of blocks so
26*44704f69SBart Van Assche# 03 appears at byte offset 48 to mean "write 4 blocks".
27*44704f69SBart Van Assche#
28*44704f69SBart Van Assche# A typical invocation in Linux and FreeBSD would look like this:
29*44704f69SBart Van Assche#    sg_raw --cmdfile=nvme_write_ctl.hex --nvm -s 2048
30*44704f69SBart Van Assche#           --infile=t.bin /dev/nvme0
31*44704f69SBart Van Assche#
32*44704f69SBart Van Assche# Notice the '--nvm' option which is needed to distinguish a NVM
33*44704f69SBart Van Assche# command from an Admin command as Admin commands are the default
34*44704f69SBart Van Assche# in this utility.
35*44704f69SBart Van Assche#
36*44704f69SBart Van Assche# This utility (and most others in the package) aligns data-in and
37*44704f69SBart Van Assche# data-out buffers to the beginning of pages which are 4096 bytes
38*44704f69SBart Van Assche# long at a minimum. This is the way NVMe likes things as well.
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